1. Field of the Invention
The present invention relates to a navigation device that searches for a route from the current location of a vehicle to a destination, and guides the vehicle along a retrieved route.
2. Description of the Related Art
Ordinary navigation devices mounted in vehicles search for a route from the current location of that vehicle to a destination, and guide the vehicle along a retrieved route. To date, various innovations have been proposed in these kinds of navigation devices. For example, in the navigation devices disclosed in JP 2001-56230 A and JP 2002-116038 A, if a vehicle that, at first, is traveling along a route obtained by an expressway-priority route search has transferred from an expressway on that route onto an ordinary road that is not part of that route due to a reason such as a traffic jam, a reroute search (reroute) is performed with ordinary road priority but not expressway priority, and route guidance for the vehicle continues to be performed along the route obtained by that reroute search. According to this kind of navigation device, in the case where a user (driver) has performed a driving operation and the vehicle has transferred from an expressway on that route onto an ordinary road that is not part of that route due to a reason such as a traffic jam, it is possible to prevent a route that includes an expressway on which a traffic jam is anticipated from being retrieved once again.
In the United States of America (USA), for example, there are corporations that provide electronic toll collection (ETC) systems, and the states in which ETC devices can be used are different for each of those corporations. ETC devices provided by some corporations cannot be used in all of the states in the USA, and the states in which use is possible from among all of those states are limited. There are cases where a fine may be imposed when a vehicle in which such an ETC device is mounted travels along an ETC device utilization road in a state in which that ETC device cannot be used.
In a navigation device mounted in a vehicle provided with an ETC device for which the usable areas (for example, states) from among a plurality of areas (for example, all of the states in the USA) are limited such as that described above, there are cases where a route that passes through a plurality of areas is obtained when a search is performed for a route from the current location of the vehicle to a destination. In these cases, a situation may arise in which the vehicle that is route-guided along that route travels along an ETC device utilization road in an area in which the mounted ETC device cannot be used. To date, no proposals have been made for a navigation device that prevents this kind of situation.